#include <stdio.h>
#include <string.h>
 
int main()
{
	char *a  = "aaaa";
	char b[5] = "bb";
	strncpy(b, a, strlen(a));
	printf("b==== %s \n", b);

	char *c  = "aaaaaaa";
	char d[5] = "bbbbb";
	strncpy(d, c, strlen(c));
	printf("c==== %s \n", d);
}